Pumps



June 27, 1967 s c m 3,327,635

PUMPS Filed Dec. 1, 1965 2 Sheets-Sheet 1 INVENTOR NORMAN His/AC a 1KATTORNEYS June 27, 1967 Filed Dec.

2 Sheets-Sheet 2 INVENTOR NORMAN H SACH [K hm M ATTORNEYS United StatesPatent ()fitice Bernese l zitented June 227, 155'? 3,327,635 PUMPF?Norman H. Sachnih, El Borado, Tex., asslgnor to Texsteani Corporation,Houston, Tex, a corporation of Texas Filed Dec. 1, i965, Ser. No.516L765 6 Claims. (Ql. Elli-d) AESTRAQT OF THE DESQLGSURE Positivedisplacement pump driven by a diaphragm motor controlled by a snap-overcenter device.

This invention relates in general to a pump, and more particularly to apositive displacement pump, and still more particularly to a singleacting, positive displacement plunger-type pump having a novel ballcheck valve.

The pump of the present invention includes an injector unit capable ofpumping high pressures and handling a wide range of volume output. Ballcheck valves are provided in the injector having novel valve seatscapable of providing absolute leak-tightness and controlled reseatingcharacteristics. Heretotore, such positive displacement plunger pumps orinjectors have employed O-ring seals or similar seals in order toeliminate leakage, and it has been found that such is generallyunsatisfactory due to the normal manufacturing tolerances in O-ringseals, and further because dilficulty is encountered in machining of thegrooves or faces which retain the seals in order to precisely controlthe amount of compression applied to the seals.

It is therefore an object of the present invention to obviate the abovenamed ditficulties and provide in a positive displacement plunger pump aleakproof, resilient seal plus controlled compression and solid seatingof the ball into the metal seat.

It is a further object of the present invention to provide in a positivedisplacement plunger pump a ball check valve including a resilient sealand a metal seat capable of providing precise control of the resilientseal in order to maintain accurate displacement of the pump volume undervarying stroke and pressure conditions.

The pump of the present invention is pneumatically operated and may beoperated by natural gas or compressed air, and includes a diaphragmmotor with spring return for operating a reciprocating piston of thepump. The piston is reciprocated by alternately charging and exhaustingthe diaphragm motor in response to piston movement. A snap-over centerdevice is provided for controlling the operation of a three-way valveeffects charging and exhausting of the diaphragm. The snap-over centerdevice includes a flipper arm connected to the valve and in turnconnected to a flipper spring that is connected to the pump plunger.Means is provided to give initial movement to the flipper arm and valveto position it between charge and exhaust positions. This means includesa bumper plate that is mounted so that it responds to movement of thepump plunger for overcoming the initial frictional forces in the valvecaused primarily by pressure differential across valve parts.

Therefore, another object of the present invention is to provide a pumphaving a diaphragm motor and a control valve for charging and exhaustingthe diaphragm motor and which is operable by a snap-over center deviceresponding to movement of the diaphragm motor, wherein means is providedto assure operation of the snap-over center device in overcomingfrictional forces in the valve, whereby the problem of pump stalling iseliminated.

Other objects, features and advantages of the invention will be apparentfrom the following detailed disclosure, taken in conjunction with theaccompanying sheets of drawings wherein like reference numerals refer tolike parts, in which:

FIG. 1 is a top plan view of the pump according to the presentinvention, with the injector head removed;

FIG. 2 is an axial sectional view of the pump taken substantially alongline 22 of FIG. 1 and also including the injector head;

FIG. 3 is a transverse sectional view taken substantially along line 33of FIG. 1;

PEG. 4 is a front elevational view of the control valve, with some partsdeleted and other parts shown in dotted lines for purposes of clarity;

FIG. 5 is an enlarged transverse sectional View of an insert seat forthe ball check valves of the present invention; and

FIG. 6 is a transverse sectional view of an insert valve body having aninsert seat therein, and being on a smaller scale than FIG. 5.

In the processing of petroleum products or in the production oftransportation of oil and gas as Well as in similar processes, it isoften necessary to inject relatively small amounts of chemicals oradditives into flow lines of varying pressure. For example, such aproblem exists in addition of emulsion breaking compounds into crude oillines. In this example, the requirements for a chemical injecting deviceare very severe in that it is essential that the proper amount ofchemical is injected into the flowing stream continually and accurately.In such a situation, the injecting device may well be open and exposedto the elements causing wide variation in ambient temperatures pluswind-blown rain, snow and dirt. An injector device may be required tocontinually inject as little as one pint of fluid per twenty-four hoursbut may on occasion be required to inject at the rate of thirty quartsper twentyfour hours for a short time to charge the system or toestablish essential concentration of the additive. Such are therequirements of injecting corrosion inhibitors as well as many otheringredients, and the present invention is capable of satisfying theserequirements.

Referring now to the drawings, and particularly to FIGS. 1 and 2, thepump of the present invention includes a body or casing 11) having aninjector head 11 at one end and a diaphragm motor 12 at the other end. Acontrol valve 13 is provided for controlling operation of the diaphragmmotor 12.

The injector head 11 includes a body 14 having a plunger or piston boss15 for slidably supporting a plunger or piston 16 operable to pump afluid through a pumping chamber 17 from an inlet 17a thereof to anoutlet 17b thereof. Suitable sealing means 18 is provided at the end ofthe plunger boss 15 to inhibit leakage of fluid from the pumping chamber17 along the plunger. The injector 11 is mounted on the body ll? of thepump by providing threads on the plunger boss 15 engageable with athreaded bore 19 in the end of the body. A lockuut 20 is provided tolock the injector 11 in proper position on the pump body 10.

A ball check valve 21 is provided at the inlet end of the pumpingchamber 17, while a ball check valve 22 is provided at the outlet end ofthe pumping chamber 17. The ball check valve 21 only permits fluid flowinto the pumping chamber, While the ball check valve 22 only permitsfluid flow out of the chamber. The ball check valve 21 includes a valveseat 21a and a ball 21b, while the ball check valve 22 includes a valveseat 22a and a ball 22b. The valve seat 21a is mounted in a fitting 23that is in turn connected to a source of fluid, while the valve' seat22a is mounted in the body 14 of the injector at the outlet end of thepumping chamber. While the ball 21b is seated by gravitational forcesand pressure thereon during the pumping stroke of the plunger 16, theball 2% is primarily seated by a spring 24 bottomed on a fitting '25that is in turn connected to a line into which predetermined measuredamounts of fluid are desired to be injected. A bleed valve 26 isprovided for bleeding of the pumping chamber 17.

The valve seats of the ball check valves 21 and 22 are identical andtherefore only one will be described. Each valve seat includes a valveinsert body 27 having a valve insert seat 28 secured therein. The insertseat 28 is secured or locked in place in the valve insert body 27 byring staking the valve body at 27a, although any other suitable means ofsecuring the insert seat may be employed. Further, any suitable sealingmeans may be provided between the insert seat 28 and the valve body toprevent leakage of fluids therealong. The valve insert body is providedwith stepped bores 29 and 3t defining a shoulder 31 therebetween,wherein the insert seat is fitted tightly within the bore 29 and inabutment against the shoulder 31. Suitable means is provided to seal theengagement between the insert seat and the bore 29. As seen particularlyin FIG. 5, the insert seat has a cylindrical outer surface 32 that isreceived in the bore 29, and internal stepped bores 33 and 34 definingtherebetween a shoulder 35. Moreover, the upper end of the bore 34 ischamfered at 38 to define the seat for a ball. The main portion of theinsert seat is metal, and an annular seal 37 of rubber or suitableresilient material is received within the bore 33 and against theshoulder 35. As a ball moves toward seated position against the seat 36,it first engages sealingly the annular rubber seal 37 providing a.leakproof valve plus control compression thereof before seating solidlyonto the metal seat and against the edge 36. The annular rubber seal 37is molded onto the metal seat to precisely control the relationship ofthe rubber dimensions relative to the rubber seat.

The plunger 1'6 is connected to a rod adapter 38 by means of a pin 39.The rod adapter is received in a bore 40 formed in one end of a thrustrod 41. A shoulder 42 is formed on the rod adapter against which the endof the thrust rod 41 abuts when driving the plunger 16 through thepumping stroke or to the right as seen in FIG. 2. A drip gland 42a isprovided at the end of the rod adapter 38 to cause any leakages from thepumping chamber 17 along the plunger rod 16 to drop to the bottom of thecasing and be expelled through a drain 4212. This precludes the fluidsfrom the pumping chamber from entering into the main body of the pumpwhich is filled with a lubricating oil and thereby contaminating the oilto cause damage to other parts of the pump. A slot 43 is formed alongthe diameter of the rod adapter 38 and coacts with an adjusting pin 44that may be adjustably arranged in holes 45, 46 or 47 of the thrust rod41. The return stroke of the plunger 16 is effected by the return strokeof the thrust rod 41 and engagement of the pin 44 against the end of theslot 43. Depending upon the position of the pin 44, the return stroke ofthe plunger 16 may be varied, and there may be a lost connection betweenthe thrust rod 41 and the rod adapter 38.

The thrust rod 41 is slidably mounted within the body and particularlyin bores provided in a housing divider 48 and a 'boss 49. The left endof the thrust rod 41 has mounted thereon a diaphragm plate 50 and adiaphragm 51 arranged in a bell-shaped chamber defined by a bellshapedportion 52 of the body 10 and a cover member 53. The diaphragmperipheral edge is secured between the portion 52 and the cover 53 whichare secured together by suitable fasteners 54. A pressure chamber 55 isdefined having an inlet 56 interconnected to a line 57. Powering of thediaphragm 51 and thrust rod 41 toward the right to effect the pumpingstroke of the plunger 16 is accomplished by connecting the pressurechamber 55 to a source of pressurized fluid, while the return stroke ofthe diaphragm and thrust rod is accomplished by a spring 58 bottomed atone end on the diaphragm plate and at the other end on a housing surface59.

The control valve 13 includes a valve body 60 mounted on the pump casing10 and extending through an opening 61 in a side Wall of the casing asseen most clearly in FIG. 3. A valve disc 62 is rotatably mounted withina recessed portion of the body and open at one side to a pressurizedfluid inlet 63 provided in a fitting 64. A suitable source ofpressurized fluid, be it natural gas or compressed air, is supplied tothe fitting 64. The valve disc 62 is resiliently held in position asshown in FIG. 3 by a spring 65. The control valve 13 is in effect athree-way rotary valve for charging and exhausting the pressure chamberof the diaphragm motor 12. The valve includes an exhaust port 66 and apressure port 67 for connecting the pressure chamber 55 to a source offluid pressure or exhaust to thereby operate the diaphragm motor 12.These ports are arranged in the valve disc 62 and adapted to be incommunication therewith for the respective charging or exhausting of thediaphragm motor. To charge the motor, the valve disc 62 is rotated sothat an aperture 67a is in line with a passageway 68 that leads to afitting 69 and the line 57, and ultimately the pressure chamber 55. Atthe same time, an aperture 67b communicates with the pressure inlet 63.For exhausting the pressure from the pressure chamber 55, .an aperture66a is aligned with the passage 68 so that the exhaust port 66 connectsthe pressure chamber to an exhaust valve 70.

through the aperture 66b of the exhaust port 66. The position of thevalve disc for exhausting is shown in FIG. 4. The exhaust valve 70 maybe adjusted to vary the exhausting of the pressure chamber to therebycontrol the speed of the pump.

Rotation of the valve disc 62 is accomplished by swinging of a flipperarm '71 that is rotatably mounted on the valve body and interconnectedwith the valve disc by means of a drive shaft 72. The flipper arm 71 hasextending normally from its free end a pin 73 having pivotally mountedthereon one end of a flipper spring 74. The other end of the spring 74is pivotally mounted on a pin 75 carried by a stirrup 76 secured on thethrust rod 41. As seen particularly in FIG. 3, the pins 73 and 75 extendso that they may engage a bumper plate 77 that is pivotally mounted on ashaft 78 carried on the back wall of the body 1%. As seen in FIG. 2, thebumper plate 77 is inverted, U-shaped and provided with upper abuttingedges 77a and 77b for engagement by the pin 75 and lower abutting edges77c and 77d for engagement by the pin 73. The flipper spring 74 togetherwith the flipper arm '71 defines a snap-over center device.

In operation, the parts shown in FIG. 2 illustrate their position at theconclusion of the pumping stroke and with the flipper arm having beenswung to the position shown in FIG. 2 so that the valve disc 62 attainsthe position shown in FIG. 4, whereby the pressure chamber 55 isconnected through the valve disc exhaust port 66 to the exhaust valvefor exhausting the pressurized fluid at a rate determined by theadjustment of the exhaust valve. When a sufiicient amount of pressurehas been released from the pressure chamber 55 and against the diaphragm51, the spring 58 will act against the diaphragm 51 and return the pumpplunger 16 on its non-pumping stroke to the left position. As it movesto its left position as seen in FIG. 2, the pin carried by the stirrup V76 engages the edge 77a of the bumper plate 77. With the pin 75 in thisposition, it has caused the center line of the flipper spring 74- tobecome coincident with the center line of the flipper arm 71. Uponfurther movement of the pin 75, it will swing the bumper plate 77 aboutits shaft toward the left as seen in FIG. 2 whereby the edge 77d strikesthe pin 73 to give an initial momentum to the bottom end of the spring74 to swing it to the left position. The bumper plate 77 thereby acts toprovide useful work to the snap-over center device at the point Where itbecomes unbalanced and further overcomes the initial frictional drag ofthe valve disc 62 caused primarily by pressure diflerential across thedisc. As the flipper arm 71 continues, the torque available increasesdue to the greater moment arm upon which the spring 74 is acting.Further, as the center line of the flipper spring 74 progresses pass thecenter line of the flipper arm 71, a torque is created by the tension ofthe spring 74 causing the flipper arm to rapidly rotate or snap past thecenter with the assist of the striking action of the pumper plate.

It will be understood that modifications and variations may be eiiectedwithout departing from the scope of the novel concepts of the presentinvention, but it is understood that this application is to be limitedonly by the scope of the appended claims.

The invention is hereby claimed as follows.

1. In a positive displacement pump having a pumping chamber and a pistonreciprocating therein, an actuator for said piston comprising, a casing,a thrust rod reciprocally mounted in said casing, means for connectingsaid thrust rod to said piston, a diaphragm motor having a housing witha diaphragm therein, said thrust rod extending into said housing, meansconnecting said thrust rod to said diaphragm, a spring return fordriving said diaphragm in one direction, and means responsive to thethrust rod for alternately charging with and exhausting from thediaphragm housing a pressurized fluid, said means including a rotarythree-way valve having an actuator interconnected with atmosphere, thediaphragm housing, and a supply of pressurized fluid, a snap-over centerdevice including a spring interconnecting the thrust rod and actuatorfor operating said valve between charge and exhaust positions, and meansfor giving initial movement to said snap-over center device, said meansincluding a bumper plate actuated by said thrust rod.

2. In a positive displacement pump having a pumping chamber and a pistonreciprocating therein, an actuator for said piston comprising, a casing,a thrust rod reciprocally mounted in said casing, means for connectingsaid thrust rod to said piston, a diphragm motor having a housing with adiaphragm therein, said thrust rod extending into said housing, meansconnecting said thrust rod to said diaphragm, a spring return fordriving said diaphrgam in one direction, and means responsive to thethrust rod for alternately charging with and exhausting from thediaphragm housing a pressurized fluid, said means including a rotarythree-way valve interconnected with atmosphere, the diaphragm housing,and a supply of pressurized fluid, a flipper arm for operating saidvalve between charge and exhaust positions, and a flipper springconnected at one end to said thrust rod and at the other end to saidflipper arm arranged to drive said flipper arm between said charge andexhaust positions upon reciprocation of said thrust rod, and means forgiving initial movement to said flipper arm as it is driven to chargeand exhaust positions.

3. In a positive displacement pump having a pumping chamber and a pistonreciprocating therein, an actuator for said piston comprising, a casing,a thrust rod reciprocally mounted in said casing, means for connectingsaid thrust rod to said piston, a diaphragm motor having a housing witha diaphragm therein, said thrust rod extending into said housing, meansconnecting said thrust rod to said diaphragm, a spring return fordriving said diaphragm in one direction, and means responsive to thethrust rod for alternately charging with an exhausting from thediaphragm housing a pressurized fluid, said means including a rotarythree-way valve interconnected with atmosphere, the diaphragm housing,and a supply of pressurized fluid, a flipper arm for operating saidvalve between charge and exhaust positions, a flipper spring connectedat one end to said thrust rod and at the other end to said flipper armarranged to drive said flipper arm between said charge and exhaustpositions upon reciprocation of said thrust rod, and a bumper platepivotally mounted on said casing and actuated by said thrust rod to giveinitial movement to said flipper arm as it is driven to charge andexhaust positions.

4. In a positive displacement pump having a pumping chamber and a pistonreciprocating therein, an actuator for said piston comprising, a casing,a thrust rod reciprocally mounted in said casing, means for connectingsaid thrust rod to said piston, a diaphragm motor having a housing witha diaphragm therein, said thrust rod extending into said housing, meansconnecting said thrust rod to said diaphragm, a spring return fordriving said diaphragm in one direction, and means responsive to thethrust rod for alternately charging with and exhausting from thediaphragm housing a pressurized fluid, said means including a rotarythree-way valve interconnected with atmosphere, the diaphragm housing,and a supply of pressurized fluid, a flipper arm for operating saidvalve between charge and exhaust positions, a flipper spring connectedat one end to said thrust rod and at the other end to said flipper armarranged to drive said flipper arm between said charge and exhaustpositions upon reciprocation of said thrust rod, a bumper platepivotally mounted on said casing, and means extending from said thrustrod for engaging said bumper plate which in turn strikes said flipperarm to impart thereto an initial movement to charge and exhaustpositions.

5. In a positive displacement pump having a pumping chamber and a pistonreciprocating therein, an actuator for said piston comprising, a casing,a thrust rod reciprocally mounted in said casing, means for connectingsaid thrust rod to said piston, a diaphragm motor having a housing witha diaphragm therein, said thrust rod extending into said housing, meansconnecting said thrust rod to said diaphragm, a spring return fordriving said diaphragm in one direction, and means responsive to thethrust rod for alternately charging with and exhausting from thediaphragm housing a pressurized fluid, said means including a rotarythree-way valve interconnected with atmosphere, the diaphragm housing,and a supply of pressurized fluid, a flipper arm for operating saidvalve between charge and exhaust positions, a flipper spring connectedat one end to said thrust rod and at the other end to said flipper armarranged to drive said flipper arm between said charge and exhaustpositions upon reciprocation of said thrust rod, a bumper platepivotally mounted on said casing, means extending from said flipper armengageable by said bumper plate, and means extending from said thrustrod for engaging said bumper plate which in turn strikes the meansextending from the flipper arm to impart thereto an initial movementtoward charge and exhaust positions.

6. In a ball check valve including a ball and a seat, the improvement inthe seat which comprises an annular metal portion having first andsecond stepped bores defining a shoulder therebetween, the first borebeing larger than said second bore, a chamfered portion at the end ofthe second bore adjacent the shoulder defining a ball seating portion,and a resilient annulus secured in said first bore against said shoulderfor engaging the ball and being compressed thereby prior to seating theball on said ball seating area to further define a seal and preventleakage through the valve.

References Cited UNITED STATES PATENTS 2,630,102 3/1953 Osburn 230-52 X2,790,460 4/1957 Radd 137-533.15 3,009,476 11/1961 Usab 137533.153,097,608 7/ 1963 Deibel et al 103-50 X 3,151,805 10/1964 Pribonic230-52 ROBERT M. WALKER, Primary Examiner.

1. IN A POSITIVE DISPLACEMENT PUMP HAVING A PUMPING CHAMBER AND A PISTONRECIPROCATING THEREIN, AN ACTUATOR FOR SAID PISTON COMPRISING, A CASING,A THRUST ROD RECIPROCALLY MOUNTED IN SAID CASING, MEANS FOR CONNECTINGSAID THRUST ROD TO SAID PISTON, A DIAPHRAGM MOTOR HAVING A HOUSING WITHA DIAPHRAGM THEREIN, SAID THRUST ROD EXTENDING INTO SAID HOUSING, MEANSCONNECTING SAID THRUST ROD TO SAID DIAPHRAGM, A SPRING RETURN FORDRIVING SAID DIAPHRAGM IN ONE DIRECTION, AND MEANS RESPONSIVE TO THETHRUST ROD FOR ALTERNATELY CHARGING WITH AND EXHAUSTING FROM THEDIAPHRAGM HOUSING A PRESSURIZED FLUID, SAID MEANS INCLUDING A ROTARYTHREE-WAY VALVE HAVING AN ACTUATOR INTERCONNECTED WITH PRESSURIZEDFLUID, A SNAP-OVER CENTER DEVICE INCLUDING A SPRING INTERCONNECTING THETHRUST ROD AND ACTUATOR FOR OPERATING SAID VALVE BETWEEN CHARGE ANDEXHAUST POSITIONS, AND MEANS FOR GIVING INITIAL MOVEMENT TO SAIDSNAP-OVER CENTER DEVICE, SAID MEANS INCLUDING A BUMPER PLATE ACTUATED BYSAID THRUST ROD.